Her recent schedule has seen a noticeable shift from the weeks prior to the surgery, when she engaged in several high-profile events.

In April, she represented the Trumps at former first lady Barbara Bush's funeral, rolled out her "Be Best" awareness campaign to help children, and orchestrated an elaborate state dinner for the Macrons of France.

Following the surgery, Melania's absence at events where the public has come to expect her alongside the president was well documented, leading her to take to Twitter to castigate reporters.

"I see the media is working overtime speculating where I am & what I'm doing," she tweeted last week, assuring she was "here at the @WhiteHouse w my family, feeling great, & working hard."

The tweet sparked a conspiracy theory that Trump himself may have written Melania's message, given that "working overtime" is a favorite phrase of the president when he tweets about the press.

Spokeswoman Grisham dismissed the media speculation as "nonsense."

"Mrs. Trump has always been a strong and independent woman who puts her family and certainly her health above all else, and that won't change over a rabid press corps," she told Fox News.

Imagination 'running wild'

White House silence, including about why Melania spent five days in hospital for a routine procedure, only fueled the speculation.

Some said Melania had moved back to New York or was cooperating with special counsel Robert Mueller, head of the main investigation into alleged Russian election meddling that President Trump has branded a "witch hunt."

Others offered she may be healing after some secret plastic surgery.

Such a weeks-long disappearance by a modern-day first lady is indeed rare, said Ohio University history professor Katherine Jellison, an expert on presidents' wives.

"I'm amazed Mrs. Trump has been able to do it," she told AFP.

The first lady is not an elected position, and Melania Trump is under no obligation to keep the American people abreast of her health, activities or whereabouts.

Several 19th century first ladies spent long periods out of view. But over the past half century, it has become the expectation that people know the basic narrative of the first lady's activities.

Melania Trump, never one to obsess like her husband about media attention, has laid low before.